1. Dismiss Notice
  2. Hey Facebook people... We've created a group for XS650.com members to connect. Check it out!
    Dismiss Notice

Help with strange triple trees issue

Discussion in 'The Garage' started by Sci85, Jan 19, 2018.

  1. Sci85

    Sci85 XS650 Addict


    I've run into an odd issue with my triple clamps. I have a cognito moto billet top triple clamp for the 35mm forks (mine's a 1980 XS). When I went to install it, the forks would not line up into the holes. After looking at it a bit, it appears that the steering stem hole does not line up with the stock stem. The hole is about 3mm to far towards the rear as seen in the photos. Anyway, they were kind enough to send me another just in case mine was cut wrong. So, I got that one the other day, and sure enough it doesn't line up either. So, are they not cutting these correct? I don't know. Maybe someone on the forum can comment from their experience.

    However, maybe somethings up with the front end of my bike? I can't imagine a steering stem getting bent, but who knows? Looking for any ideas here.

    Anyway, can some one also give me the center to center measurements for a 35MM fork year and stock front end? I'm looking for fork to stem and fork to fork. Thanks so much!

    Attached Files:

  2. bikefreak69

    bikefreak69 XS650 Enthusiast

    I was going to purchase a set of those clamps for my fork conversion,but having second thoughts after seeing this post.
  3. Beags64

    Beags64 XS650 Junkie Top Contributor

    '78 Spcl. looks to be 185mm fork to fork, 47.5mm fork to stem +/-
    Sci85 likes this.
  4. gggGary

    gggGary Stop that! XS650.com Supporter Top Contributor

    I don't see any provisions to clamp the stem with that triple? Yeah from your pics it looks like their cad file is wrong. I note they list only one part number for XS650 69 to 73 and that ain't right either, there's some dimension changes in those years. There's a lot involved in making replacement parts for a bike that was sold for 15 years.
    Jim and solo2racr like this.
  5. Jim

    Jim Beyond the edge is the unknown. Here be Dragons XS650.com Supporter Top Contributor

    Looks like your original tree fits just fine, so I'll agree with Gary... bad CAD file.
    No stem or fork tube clamping... I wouldn't use it if it did fit.
    MrBultaco likes this.
  6. halfmile

    halfmile XS Builder XS650.com Supporter Top Contributor

    Did you loosen the bottom clamps before you tried to fit the upper??
  7. gggGary

    gggGary Stop that! XS650.com Supporter Top Contributor

    Jim likes this.
  8. gggGary

    gggGary Stop that! XS650.com Supporter Top Contributor

    Agree; I came up with 184mm and 47.27mm there was a little wiggle because I didn't clamp the tubes.
    Jim and Sci85 like this.
  9. 5twins

    5twins XS650 Guru Top Contributor

    I don't see how it would clamp the tubes. I don't see a slit anywhere. Unless it just deforms the round hole slightly when tightened down? Can't say I'm crazy about that design, lol. Think I'd be spending my money on something else. Besides, the top tree isn't considered a major weak point on these bikes as far as I know.
    Jim likes this.
  10. gggGary

    gggGary Stop that! XS650.com Supporter Top Contributor

    This shot shows the clamp a bit better

    didn't find any better info maybe Sci85 can show us the bolt/clamp assembly out of the triple?
    Jim likes this.
  11. Sci85

    Sci85 XS650 Addict

    Thanks guys. I liked the design and cleaned up my dash area since I wasn't going to run the original speedo setup. There's no slit in the fork clamp but instead uses a pretty clever part that squeezes the fork via a piece that is cut to match the inside of the clamp curve and is tightened via an allen screw . You can just see it in the pic on the right side fork hole by gggGary.

    I'll check the center to center measurements tomorrow and report back. Thanks Beags64 and gggGary for those.

  12. fredintoon

    fredintoon Fred Hill, S'toon. Top Contributor

    Hi Sci,
    one thing I don't see mentioned in this string is:-
    Do you have a stock upper tree to compare the Cognito tree to?
    Jim likes this.
  13. Jim

    Jim Beyond the edge is the unknown. Here be Dragons XS650.com Supporter Top Contributor

    Yeah, that's what I was trying to get at in my comment (#5) above Fred. The first post shows the new tree that don't fit in the pic on the left. The pic on the right shows the same bike with the stock tree that does fit. If the original fits... and apparently it does.... there ain't nothing wrong with the bike, it's the new part.
    Last edited: Jan 20, 2018
  14. gggGary

    gggGary Stop that! XS650.com Supporter Top Contributor

    I'm assuming he has the stock triple, it's the same bike in both pics.
    Jim likes this.
  15. I think the early triple trees (XXXX-1972) had a longer distance between the centerline of the forks and the centerline the stem pivot – I have a (PO modified) 1972 frame with "late model" (1976) trees and lock to lock has limited travel. what is your measurement ( current) on the stock distance?
    Thanks Dom
  16. Sci85

    Sci85 XS650 Addict

    Ok I measured the same 184mm fork to fork but I'm measuring 104mm from fork tube to stem (center to center). 47mm seems way off. Are we measuring the same thing?

    I'm gonna call Cognito this week and see what's up.
    Last edited: Jan 21, 2018
  17. gggGary

    gggGary Stop that! XS650.com Supporter Top Contributor

    We are measuring set back from a line drawn between the tube centers.
    Dimensions are always taken in 2 perpendicular directions almost never at angles.
    Not least because that's how milling machines move.
    Last edited: Jan 22, 2018
    Jim and Sci85 like this.
  18. Sci85

    Sci85 XS650 Addict

    Ah, got it. Thanks gggGary!
  19. TwoManyXS1Bs

    TwoManyXS1Bs BBQ Hunter Top Contributor

    Jim likes this.
  20. Sci85

    Sci85 XS650 Addict

    I spoke with Cognito folks. I'm sending the clamp back for them to check into what's going on. But, before I do, I want to make certain it's the clamp and not the bike. Anyway, I'm curious what the measurments are from an earlier model bike. Maybe they used the 34mm dimensions and just cut the fork holes to 35mm.

    Can someone get the fork to stem hole measurement from an earlier 34mm model for me?

    Thanks again guys. We will solve this mystery!

Share This Page